[kvm-unit-tests PATCH v3 3/5] riscv: Add method to probe for SBI extensions

[Andrew Jones]

On Fri, Jul 19, 2024 at 10:39:45AM GMT, James Raphael Tiovalen wrote:
> Add a `sbi_probe` helper method that can be used by SBI extension tests
> to check if a given extension is available.
>

Suggested-by: Andrew Jones <andrew.jones at linux.dev>

> Signed-off-by: James Raphael Tiovalen <jamestiotio at gmail.com>
> ---
>  lib/riscv/asm/sbi.h |  1 +
>  lib/riscv/sbi.c     | 10 ++++++++++
>  2 files changed, 11 insertions(+)
> 
> diff --git a/lib/riscv/asm/sbi.h b/lib/riscv/asm/sbi.h
> index d82a384d..5e1a674a 100644
> --- a/lib/riscv/asm/sbi.h
> +++ b/lib/riscv/asm/sbi.h
> @@ -49,6 +49,7 @@ struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
>  
>  void sbi_shutdown(void);
>  struct sbiret sbi_hart_start(unsigned long hartid, unsigned long entry, unsigned long sp);
> +long sbi_probe(int ext);
>  
>  #endif /* !__ASSEMBLY__ */
>  #endif /* _ASMRISCV_SBI_H_ */
> diff --git a/lib/riscv/sbi.c b/lib/riscv/sbi.c
> index f39134c4..7d7d09c3 100644
> --- a/lib/riscv/sbi.c
> +++ b/lib/riscv/sbi.c
> @@ -38,3 +38,13 @@ struct sbiret sbi_hart_start(unsigned long hartid, unsigned long entry, unsigned
>  {
>  	return sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_START, hartid, entry, sp, 0, 0, 0);
>  }
> +
> +long sbi_probe(int ext)
> +{
> +	struct sbiret ret;

Let's also add

  ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_SPEC_VERSION, 0, 0, 0, 0, 0, 0);
  assert(!ret.error && ret.value >= 2);

> +
> +	ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_PROBE_EXT, ext, 0, 0, 0, 0, 0);
> +	assert(!ret.error);
> +
> +	return ret.value;
> +}
> -- 
> 2.43.0
>

With that addition,

Reviewed-by: Andrew Jones <andrew.jones at linux.dev>

Thanks,
drew